Follow-up after pyeloplasty: How long?

Indian Journal of Urology | July-September 2008 | catheterization time, blood loss and hospital stay in favor of the Thulium laser. Unlike KTP, ThLRP retrieves prostatic tissue for biopsy, has a shorter learning curve than HoLEP. The operative technique most closely resembles TURP as compared to other lasers. Before this technique becomes widely accepted, we await experience from other centers with longer follow-up. However, it is becoming increasingly evident that TURP is facing genuine competition and might be replaced as the gold standard in minimally invasive surgery of the prostate.


SUMMARY
This was a retrospective study of 138 patients who underwent a successful dismembered pyeloplasty over an eight-year period. [1] Patients were divided into three groups based on the duration of follow-up with renal scans. Group one (138) had a renal scan at a mean of nine months after surgery and the split renal function (SRF) before and after surgery was compared. Group two (35) had a second scan at 3.5 years after surgery and group three (29), in addition, had another scan at 5.5 years. The SRF of the scan after surgery and the late scan at 3.5 and 5.5 years were compared. A change in SRF of greater than 5% was considered signiÞ cant. The mean (range) SRF was marginally better in all three groups at follow-up. Repeat renal scans at 3.5 and 5.5 years after surgery showed stable SRF, even if the renal function was already diminished. Of 138 patients, only Þ ve had a signiÞ cant deterioration in SRF to less than 40%. Hence, the authors have concluded that repeat renal scans in a Þ ve to seven-year period after pyeloplasty don't seem to be justiÞ ed, as most renal units remain stable.

COMMENTS
Dismembered Anderson-Hynes pyeloplasty is a successful treatment for ureteropelvic junction (UPJ) obstruction with success rates as high as 98%. [2] Long-term data in adults Uroscan has shown Þ ve to 15-year durability of success. [3] For these reasons, dismembered pyeloplasty remains the Þ rst line surgical procedure for the majority of pediatric urologists.
DeÞ ning a true UPJ obstruction in the pediatric population remains difficult. Serial ultrasounds, measurement of resistive index (RI) using duplex ultrasonography and intravenous urography are few of the various modalities used. Radionuclide renography is one of the modalities with objective measurements. Calculation of SRF and assessing wash out curves is important in the diagnosis and followup. However, there are only a few reports in children on how long these patients need follow-up. Also, little is known about the long-term renal function on consecutive renal scans, especially whether loss of renal function in the absence of obstruction might progress with time. The authors have attempted to answer some of these questions.
Apart from the retrospective design, one of the major drawbacks of this study is that the majority of the patients with an immediate postoperative SRF more than 40% were discharged from follow-up assuming that their renal function would remain stable. Hence, only 29 of the 138 patients had follow-up scans at a mean of 5.5 years.
O'Reilly et al. performed a repeat renal scan in 24 patients at 6-19 years after surgery and concluded that the results were durable. [4] Another study by Boubaker et al. showed that after an unobstructed diuretic renogram, recurrence of the obstruction was unlikely and did not justify a longterm follow-up. [5] One of the concerns advocating follow-up of post pyeloplasty children is the early detection of renal functional loss. The use of SRF as a tool for follow-up may not actually reß ect the natural course of previously obstructed kidneys as a decrease in SRF might be either due to deterioration of the operated kidney or due to contralateral compensation. This study had no data to estimate absolute single-kidney function and therefore no Þ rm conclusions could be drawn about the recovery or deterioration of the affected kidneys.
Boubaker et al. using accumulation index (AI) as an indicator of absolute function, reported that in 53 children who had surgery because of presumed UPJ obstruction, the AI improved in 88% after 5-15 years of follow-up; the improvement was most notable in those with impaired renal function before surgery. [6] In conclusion, this study does show that most renal units remain stable after a successful pyeloplasty. But further studies are required to investigate whether previously obstructed kidneys will deteriorate in time, and to determine which patients with poorly functioning kidneys after pyeloplasty are at risk of developing hypertension, infection, proteinuria or pregnancy-related problems.

SUMMARY
Petterson et al., [1] identiÞ ed 16,983 Swedish men from the Swedish Hospital Discharge Register who underwent orchidopexy for undescended testis, between 1964 to 1999. As almost all patients in Sweden are treated at public hospitals, this data was fairly comprehensive. Subjects who underwent orchidopexy before the age of 20 years were included. Two hundred and Þ ve men who emigrated from Sweden after surgery but did not immigrate back before the start of their follow-up and one who had testicular cancer at the time of beginning the study were excluded. Other exclusion includes those with ambiguity on information on date of orchiodopexy or sex. The subjects were followed from 15 years of age or the age of orchidopexy plus one year, whichever occurred earlier, till the date of diagnosis of testicular cancer, upper age limit of 55 years, emigration, death, or December 2000. The authors have calculated the expected period-speciÞ c incidence for Þ ve-year age periods, based on the incidence in the Swedish general population. Based on the observed number of cases in the study population, the relative risk was estimated. They used a number of covariate analyses, including separation of the follow-up into three distinct calendar periods, time of orchidopexy and the place where orchidopexy was performed. Further statistical analysis using Schoenfeld residuals indicated that the assumption of hazard ratio was correct, and all such confounders were eliminated.
The mean follow-up was 12.4 years. Mean age at orchidopexy was 8.6 years. Though only 20 cases was expected in the study group based on the incidence in the general population, 56 were documented. The standardized incidence ratio of testicular cancer in those undergoing orchidopexy before the age of 13 years was 2.23, as opposed to those above the age of 13 years, where it was almost double at 5.40.